Current time in Korea 10:01 Sep 25 (Fri) Year 2020 KCS KCS Publications
KCS Publications
My Journal  Log In  Register
HOME > Search > Browsing(BKCS) > Archives

Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 1, Number 2
February 20, 1980 

Photocyclization of 1,2-Bispyrazylethylene and 2-Styrylpyrazine
Sang Chul Shim, Suk Kyu Lee
1,4,5,8-Tetraazaphenanthrene, a new tetraazaheteroaromatic compound, has been synthesized photochemically in 90 % yield and quantum yield of 5.1 × 10-2 from dilute benzene solutions of 1,2-bispyrazyl ethylene(BPE) in the presence of oxygen as an oxidant. Iodine was not appropriate oxidant because of strong complexing with BPE and also enhanced intersystem crossing of BPE and thereby decreasing the photocyclization of BPE. Salt effect, solvent effect, and quenching and sensitization studies on the photocyclization of BPE have shown that l(n,π*) is the reactive state for the cyclization in comparison to l(π,π *) state for the ordinary stilbene derivatives.
68 - 70
Full Text